Path of the Machine

Barbarians who follow the Path of the Machine are built to be weapons of war, altering their bodies and grafting weapons onto themselves. By replacing their hearts with an engine, such barbarians have enhanced endurance and power compared to others. The rage they experience is from the anguish of undergoing these modifications.

Overcharge

Starting when you choose this path at 3rd level, you can overcharge when you rage as bonus action If you do so, you can choose to channel the power of your engine into your movements or attacks, increasing your movement speed by 10 feet until the end of your next turn, or dealing an additional 1d4 fire or lightning damage on your next melee attack.

Augmentation

Starting when you take this path at 3rd level, your begin to modify your body and your heart is replaced by an engine. You are able to graft weapons and shields onto your body by paying an amount of gold equal to the item's cost. The weapon must have the one-handed property. By doing so, you are considered to be wielding the weapons and shields you've grafted, but your hands are free for the purposes of interacting with objects, performing somatic components, and whatever else your DM allows.

Enhanced Augmentation

Beginning at 6th level, you can’t gain a 6th level of exhaustion. You also have advantage on saving throws against being restrained and grappled

Heat Sink

Starting at 6th level, whenever you hit a creature make a melee attack, you can have that creature make a Constitution save throw (DC equal to 6 + your proficiency bonus + your Strength modifier.) On a failed save, the creature takes fire damage equal to your barbarian level, and you take half as much damage rounded down. On a success, you are unable to channel your excess heat properly and you take fire damage equal to half of your barbarian level rounded down.

Iron Visage

Beginning at 10th level, when you rage and use your overcharge feature, any non-friendly creature that can see or hear you must succeed on a Wisdom saving throw (DC equal to 8 + your proficiency bonus + your Charisma modifier) or be frightened of you until the end of your next turn.

Creatures that succeed their saving throw become immune to this feature for the next 24 hours.

Once you use this feature, you cannot use it again until your finish a long rest.

External Cooling Foil

Starting at 14th level, the amount of heat radiating from you is too much for others to handle. When a creature ends its turn within 5 feet of you, it must succeed a Constitution saving throw (DC 10 + your Charisma modifier) or take fire damage equal to 1d8 + your proficiency bonus.